After many years, I finally learned which is a sweet potato and which is a yam. There are a lot of botanical differences that don’t matter much to me, but at least I know now: the orange-y fleshed ones are yams. The pale fleshed ones are sweet potatoes.
Photo from thekitchn.com
Sweet potatoes and/or yams are wildly nutritious and are at their best in the fall and winter. My husband loves them and I have been looking for good ways to prepare them – I am not a fan of the marshmallow-gunk-topped ones. Despite what Alton Brown says, roasting is the best way to cook them. It takes time but they turn out wonderfully sweet.
I came across a recipe for Sweet Potato Bisque in Anna Thomas’s Love Soup cookbook. Her version included a celery root, which I did not have on hand and didn’t feel like driving to buy. I figured some regular old celery would work just fine. I made some other adaptations and simplified her recipe. I much prefer yams over sweet potatoes but Yam Soup just doesn’t have that certain cachet, so Sweet Potato Soup it is.
SWEET POTATO SOUP
- 2 large yams
- 2 celery stalks, chopped
- broth of your choice (vegetable, chicken, mix of water and white wine, whatever)
- 1 large onion, chopped
- olive oil
- 1 teaspoon sage
- 1 teaspoon thyme
- salt and pepper
Wash the yams, stab them all over with the point of a knife, and put them on a piece of aluminum foil on the rack of the oven. Turn the oven temperature to 350 and cook the yams until they are tender (give them a squeeze with a mitt-protected hand) and oozing caramelized juices (this is why you use foil). Remove from oven and let cool until you can handle them without burning yourself.
Heat about a tablespoon of olive oil in a skillet and add the chopped onion. Cook over medium heat, stirring often, until onion is lightly browned and caramelized. After about 20 minutes, add the sage and thyme and let them cook with the onions another 10 minutes or so.
Peel the yams and cut into slices. Put them in a large-ish pot with about 4 cups water or broth and the chopped celery. Bring to a simmer and let cook slowly about 20-30 minutes.
Add the onions to the yams and cook them together another 10 minutes. Turn the heat off and let them cool a bit, then puree them in batches in a blender or food processor. You will probably need more broth to puree the yams.
Return pureed soup to soup pot. Add a good sprinkle of cayenne and more broth if needed to make it the consistency you like. Taste for salt and adjust seasoning.
Serve as is, or stir in some cream/half and half. Garnish with some toasted sliced almonds or some salsa/Sriracha.
This makes about 2 quarts.